This invention relates to dispensing means, particularly, but not exclusively, for beverages made by mixing beverage constituents. It has particular application in the field of soft drinks such as colas or flavoured sodas but it will be appreciated that it is not limited thereto.
Beverages may be dispensed, for example, using a dispense tower which is raised above a serving table level to provide beverage outlets through dispense valves located at or about shoulder height. The tower contains pipework for carrying the beverage ingredients and its outer surface frequently carries advertising material for the beverage(s) to be dispensed.
The tower may have multiple outlets at its upper end, the outlets forming a horizontal line of dispense valves. This permits more than one beverage to be dispensed simultaneously and it is possible to have a number of different beverages dispensable from a single tower.
In the case of beverages such as colas, the tower may carry pipework for chilled soda (carbonated water) and for a cola or other flavoured syrup. The separately supplied soda and syrup are then mixed together in the correct proportions at the outlet in a specially-designed dispense valve known as a post-mix dispense valve. A still water supply may also be required so that still beverages can be mixed and dispensed.
The present invention is applicable to such an arrangement but, again, is not limited thereto. Thus the apparatus of the invention may be applied to a series of separate dispense heads or to a single all-embracing dispense head.
The present invention aims to provide an improved mixing and dispensing means whereby the amount of each fluid to be dispensed can be accurately controlled.
Accordingly, the invention provides a beverage dispense apparatus comprising a dispense head having one or more outlets for fluids to be dispensed, a fluid supply line to the head for each fluid, each outlet being governed by a valve, a valve actuation means to open and close each valve, a flow sensor positioned in each fluid supply line and connected to a control means which controls the valve actuation means whereby it actuates opening of its respective valve on receiving a start signal and actuates closing of the valve when the pre-determined amount of fluid flow has been achieved, the valve of each outlet comprising a housing containing a passageway between an inlet and an outlet of the valve, a closure member movable in the passageway from a first position in which the valve is fully closed to a second position in which the valve is fully open, the closure member engaging the wall of the passageway to seal the passageway, the wall of the passageway and/or the closure member defining at least one groove, the groove having a transverse cross section that increases in area in the downstream or upstream direction, whereby movement of the closure member from the first position towards the second position opens a flow channel through the groove.
A start signal may conveniently be given by pressing an appropriately marked button on the dispense head for the desired beverage from the range of beverage options offered by the apparatus. The start signal activates the control means, which may conveniently be electronic.
Alternatively, each beverage option may have a code which is keyed into the apparatus to give the appropriate start signal.
The flow sensor may be of any convenient type. Thus, for example, it may be an ultra-sonic sensor or a flow sensing turbine of the types well-known in the art.
The valve actuation means may be, for example, a stepper motor, e.g. of the pulsed, magnetically driven type, a proportional solenoid actuator or the like. Alternatively the actuation means may be hydraulic, or pneumatic or any suitable combination e.g. electromechanical.
Thus the valves can be controlled to govern the proportions of fluids that are fed to and mixed at the head prior to dispense. Alternatively they can be controlled to provide a predetermined volume of a single fluid.
In addition to blending beverage constituents, e.g. to provide lower or higher carbonated colas, the apparatus may be used to blend warm and cold fluids together by the incorporation of a temperature sensor to give a mixed beverage of predetermined temperature.
As indicated above, the valves have a groove construction, i.e. the valve closure member and the wall of the passageway containing the valve closure member define between them one or more grooves, e.g. a pair of diametrically opposed grooves, the grooves extending and increasing or decreasing in cross-sectional area along the axial length of the passageway, whereby opening and closing of the valve exposes more or less of the groove volume to increase/decrease the volume of the passageway through the valve. The grooves may, for example, increase in cross-sectional area in the downstream direction.
The grooves may be of a xe2x80x9cVxe2x80x9d cross-section but other shapes, e.g. circular or rectangular cross-section may be utilised, if desired. For convenience, however, the grooves will hereafter be referred to as V-grooves.
The grooves may, for example, be cut or moulded into the material of the passageway wall or closure member by conventional means depending on the material used..
The grooves are preferably V-grooves that widen along their length at an angle of from 1xc2x0 to 20xc2x0.
Where more than one groove is provided in the passageway, it is not essential that all the grooves are positioned to commence and finish at the same distance along the passageway.
The valve closure member may carry one or more sealing rings to engage the wall of the passageway in the first position, i.e. the closure member may engage the wall of the passageway by means of the sealing ring(s) to close the outlet or, alternatively, the closure member and passageway may be a precision fit in the first position to close the outlet without a seal.
As indicted above, depending on the desired particular construction, the V groove or grooves in the passageway may increase in cross-sectional area in the upstream or downstream direction. In the latter case, the valves have the added advantage of having greater self-cleaning properties, i.e. larger particles can pass more readily through the valve in the open position without causing partial blockage than for a conventional valve having an annular passageway of the same throughput.
Conveniently the passageway and closure member are of generally cylindrical transverse cross-section and a pair of grooves may be opposed diametrically across the passageway. However, it will be appreciated that the invention is not limited to such constructions.
The progressive increase or decrease in area of the V-groove flow channels can provide excellent linear flow through the valves.
Where the flow sensor is of the ultra-sonic type it may be of a construction generally known per se. Essentially, such a sensor comprises a piezo-electric crystal member which emits ultra-sonic pulses when an electrical signal is applied to it. The member can also receive ultrasonic pulses and produce an electrical output signal therefrom. A sensor is positioned at each end of a flow passage for the fluid and an ultra-sonic pulse is passed through the fluid from the upstream to the downstream sensor and then a pulse is passed through the fluid from the downstream sensor to the upstream sensor. Thus the signals are measured in two directions through the flowing fluid and the thus monitored flow is signalled to the electronic control unit. It will be appreciated that the signal flight time may vary with fluid density, viscosity and temperature and the control unit will be pre-programmed accordingly.
The piezo-electric sensors may conveniently each be designed as a unit to plug into a suitable housing in the wall at each end of the flow passage whereby they can pulse through the wall. Thus the sensor units may be removed without breaching the passageway.
Moreover, the flow passage may be angled e.g. may be L-shaped, with a reflector at the corner of the angled passage to reflect the ultrasonic signals around the bend of the angle. The angle may be, for example, about 90xc2x0 but other angles may be utilised as convenient. This angling of the passage enables the sensor unit to be packaged into a smaller volume.